Legg-Calve-Perthes Disease in Emergency Medicine 

Updated: Mar 03, 2018
Author: Jessica Hernandez, MD; Chief Editor: Trevor John Mills, MD, MPH 


Practice Essentials

Legg-Calvé-Perthes disease is the eponym given to idiopathic osteonecrosis of the femoral head. It was described approximately 100 years ago as a unique disease entity affecting the pediatric population.[1] Legg-Calvé-Perthes disease may result in femoral head deformity and degenerative joint disease. The femoral head may be distorted permanently. The younger the age of onset of Legg-Calvé-Perthes disease, the better the prognosis. Children older than 10 years have a very high risk of developing osteoarthritis. Most patients have a favorable outcome. Prognosis is proportional to the degree of radiologic involvement.[2, 3, 4, 5]

The exact etiology of Legg-Calvé-Perthes disease remains unclear, but it is likely multifactorial and may include genetic predisposition, environmental exposures, and/or socioeconomic factors.[6]  Some specific suggested causes include trauma, an inflammatory process, a disorder of the epiphyseal cartilage, abnormalities in the vasculature,[7] increased blood viscosity such as thrombophilia, abnormalities in growth hormone, maternal smoking, and second-hand smoke exposure.[6, 8]


The pathophysiology and temporal sequence of events in Legg-Calvé-Perthes disease remains unclear; however, the following scenario is generally accepted:

  1. The blood supply to the femoral head is interrupted.[9]

  2. Bone infarction and necrosis affects the articular cartilage, subchondral bone, and the bony epiphysis.[8]

  3. Revascularization occurs and new bone ossification starts. In some cases, patients may have normal bone growth and development.

  4. With progression of the disease, bone resorption, delayed bone formation, and subchondral fracture occurs. This microdamage is usually the result of normal physical activity, not direct trauma.

  5. This may result in deformities in the femoral head, epiphyseal growth plate, and possible lesions in the metaphysis.[8]


One in 1200 children younger than 15 years is affected by Legg-Calvé-Perthes disease. Legg-Calvé-Perthes disease most commonly is seen in persons aged 3-12 years, with a median age of 7 years.The disease is familial approximately 10% of the time.[10]  

Legg-Calvé-Perthes disease is a self-limited disease if not treated. Outcome widely varies. In 15-20% of patients with Legg-Calvé-Perthes disease, involvement is bilateral.

Whites are affected more frequently than persons of other races. Males are affected 4-5 times more often than females.

In a study of girls with Legg-Calvé-Perthes disease, of the 451 patients who presented at a single large urban children's hospital from 1990-2014 with a diagnosis of Legg-Calvé-Perthes disease, 82 (18.2%) were female. The average age at presentation for girls was 6.58 years.[11]

Signs and symptoms

Symptoms of Legg-Calvé-Perthes disease usually have been present for weeks because the child often does not complain. Radiographs of the hip should always be considered for a child complaining of thigh or knee pain.

History may reveal the following:

  • Hip or groin pain, which may be referred to the thigh

  • Mild or intermittent pain in anterior thigh or knee

  • Limp

  • Usually no history of trauma

  • Progressively increased pain with physical activity, usually relieved by rest.[10]

Physical examination findings and symptoms may include the following:

  • Decreased range of motion (ROM), particularly with internal rotation and abduction

  • Painful gait

  • Muscle spasm

  • Limp

  • Leg length inequality due to collapse of the femoral head

  • Thigh, calf, and buttocks muscle atrophy: Circumferences on the involved side may be smaller than on the unaffected side, secondary to disuse.

  • Short stature, resulting from deformity of the femoral head.

  • Roll test: With patient lying in the supine position, the examiner rolls the hip of the affected extremity into external and internal rotation. This test should invoke guarding or spasm, especially with internal rotation.

  • Trendelenburg sign: While standing, the patient lifts one leg up at a time; because of muscle weakness on the affected side, the pelvis drops to the opposite side.[10]


Plain radiographs of the hip, including anteroposterior and frog-leg views, are the preferred diagnostic tests.

When the diagnosis of Legg-Calvé-Perthes disease is unclear, initial laboratory studies can aid in ruling out other diagnoses. CBC count, erythrocyte sedimentation rate, and C- reactive protein evaluation may be helpful to evaluate for suspected infection.

Hip aspiration with fluid analysis can be performed if a septic joint is suspected.

Multiple radiographic classification systems exist,   based on the extent of abnormality of the capital femoral epiphysis. Waldenstrom,   Catterall,   Salter and Thompson, and Herring are the 4 most common classification systems.[3, 12, 13, 14, 15, 16, 17, 18, 5]





Imaging Studies


Plain radiographs of the hip, including anteroposterior and frog-leg views, are the preferred diagnostic tests. These are extremely useful in establishing the diagnosis. (Several radiographs are shown below.)

Legg-Calvé-Perthes disease. Image shows subchondra Legg-Calvé-Perthes disease. Image shows subchondral sclerosis and radiolucency in the left femoral head (stage II disease). The femoral head is slightly smaller on the left than the right.
Legg-Calvé-Perthes disease. The left subchondral r Legg-Calvé-Perthes disease. The left subchondral radiolucency is more readily demonstrated on a frog-leg view and represents subchondral fracture.
Legg-Calvé-Perthes disease. Image shows left femor Legg-Calvé-Perthes disease. Image shows left femoral subchondral sclerosis and radiolucency.
Legg-Calvé-Perthes disease. Image shows flattening Legg-Calvé-Perthes disease. Image shows flattening and early fragmentation of the left femoral head with the presence of femoral neck cysts. The femoral head is obviously smaller on the left than on the right.

Multiple radiographic classification systems exist,[12] based on the extent of abnormality of the capital femoral epiphysis. Waldenstrom,[13] Catterall,[3] Salter and Thompson, and Herring are the 4 most common classification systems. No agreement has been reached as to the best classification system.

Five radiographic stages can be seen by plain radiography. In sequence, they are as follows:

  • Cessation of growth at the capital femoral epiphysis; smaller femoral head epiphysis and widening of articular space on affected side

  • Subchondral fracture; linear radiolucency within the femoral head epiphysis

  • Resorption of bone

  • Reossification of new bone

  • Healed stage

Other imaging studies

Technetium Tc-99m bone scanning can be used to detect early disease or define the extent of ischemia, as well as to predict severity. Currently, this type of study is not in high use because of radiation exposure and the lack of anatomic detail of the femoral head and its relationship to the acetabular fibrocartilage.[19]

Dynamic arthrography can provide early information by assessing the degree of flattening and amount of cartilaginous extrusion; however, it remains an invasive procedure and is difficult to repeat.[19]

A review of the literature has proposed MRI as a valuable modality to evaluate Legg-Calvé-Perthes disease,[20] especially with the use of newer sequences such as delayed gadolinium enhancement (to depict cartilage) and diffusion-weighted sequences (to assess cartilage repair).[19] However, under current American College of Radiology guidelines, MRI evaluation is not the initial test of choice.[21, 22, 23, 5]

An example of an MRI depicting Legg-Calvé-Perthes disease is shown below.

Legg-Calvé-Perthes disease. Coronal T1-weighted im Legg-Calvé-Perthes disease. Coronal T1-weighted image demonstrates irregularity and distortion of the right femoral head in this 7-year-old child with known Legg-Calvé-Perthes disease. Image courtesy of Radiopaedia.org, contributed by Dr. Roberto Schubert, published at http://radiopaedia.org/cases/legg-calve-perthes-disease-4.

Ultrasonography is less helpful for the diagnosis of Legg-Calvé-Perthes disease because it provides limited evaluation of osseous structures; however, it may be used to evaluate for effusion.



Emergency Department Care

Goals of treatment of Legg-Calvé-Perthes disease include the following:

  • Containment of the femoral epiphysis within the confines of the acetabulum

  • Maintenance or improvement in range of motion

  • Relief of weight bearing

  • Provision of traction

  • Prevention of deformity and growth disturbances

  • Prevention of degenerative arthritis[10]


Once the diagnosis of Legg-Calvé-Perthes disease is suspected, an orthopedic surgeon or a pediatric orthopedic surgeon should be contacted for further management decisions.

An orthopedic consultant may choose to order more specialized tests (eg, bone scintigraphy, arthrography, MRI), usually in an outpatient setting, to better determine the extent of the disease.

Management is based on the age of onset and is divided into patients younger than 6 years, patients aged 6-8 years, and patients older than 8 years.[9]

Ultimately, patients can be managed either conservatively or operatively. This is decided on a case-by-case basis by the orthopedic specialist.

Medical Care

Legg-Calvé-Perthes disease does not require emergent inpatient care. Initially, close follow-up is required to determine the extent of necrosis.Treatment may involve observation, usually in children younger than 6 years. Bed rest and abduction stretching exercises are recommended. Nonsurgical containment allows the femoral head to stay within the acetabulum, where it can be molded. Various casts, braces, and crutches have been used for containment.

Once the healing phase has been entered, follow-up can be every 6 months. Long-term follow-up is necessary to determine the final outcome.

Surgical treatment may benefit older patients; however, the ability of surgical treatment to achieve a normal hip at maturity is modest.[9, 24] Surgical correction of gross deformities of the femoral head may be necessary. Some studies have demonstrated that patients aged 6 years or older treated conservatively fared worse than those treated with surgery.[6]  In contradistinction, other studies show that surgical management in younger children does not improve long-term outcome.[2, 20, 25]



Medication Summary

Medical treatment does not stop or reverse the bony changes. Recent experimental studies have demonstrated some success with antiresorptive and anabolic agents for the treatment of Legg-Calvé-Perthes disease. However, further studies are needed to assess the safety and effectiveness in humans.[8]

In the emergency department setting, the focus should be on administering appropriate analgesic medication.

Nonsteroidal anti-inflammatory drugs (NSAIDs)

Class Summary

These drugs most commonly are used for the relief of mild to moderately severe pain. Although the effects of NSAIDs in the treatment of pain tend to be patient specific, ibuprofen is usually the drug of choice (DOC) for the initial therapy.

Ibuprofen (Advil, Motrin IB, Caldolor, I-Prin, Provil, NeoProfen, Genpril)

Ibuprofen is usually the DOC for the treatment of mild to moderately severe pain if there are no contraindications. It inhibits inflammatory reactions and pain, probably by decreasing the activity of enzyme cyclooxygenase, thus decreasing prostaglandin synthesis.

Ketoprofen (Active-Ketoprofen, Frotek, Ketophene Radiopaq)

Ketoprofen is used for the relief of mild to moderate pain and inflammation. Small doses are indicated initially in patients with small body size, elderly patients, and persons with renal or liver disease. Doses of over 75 mg do not increase therapeutic effects. Administer high doses with caution, and closely observe the patient for response.

Naproxen (Aleve, Naprosyn, Anaprox DS, Naprelan)

Naproxen is used for the relief of mild to moderate pain. It inhibits inflammatory reactions and pain by decreasing the activity of cyclo-oxygenase (COX), which is responsible for prostaglandin synthesis.


Class Summary

Pain control is essential to quality patient care. It ensures patient comfort, promotes pulmonary toilet, and relieves pain.

Acetaminophen (Tylenol, Acephen, Aspirin-Free Anacin Extra Strength, Mapap, Ofirmev)

Acetaminophen is the DOC for the treatment of pain in patients with documented hypersensitivity to aspirin and NSAIDs, as well as those with upper GI disease or those who are taking oral anticoagulants.